Rules of Thumb

You can use the conditional operators to compare strings just as you do for numeric values. Generally, string comparisions follow these rules of thumb:

• Uppercase letters are less than lowercase letters, so "ABC" comes before "abc"
• Letters compare in alphabetical order, so "A" is less than "B" and the name "Walter" is greater than (comes before) "Williams".
• Numbers are less than letters, so "5" is less than "Five".

VB supports a special statement in the declaration section of a module that reads as follows: Option Compare Text If this statement appears in a modules declarations section, uppercase and lowercase letters compare equally.

VB supports another conditional operator, Like, which compares values based on a wildcard match. This operator uses * for zero or more characters, ? for only one character, # for a numeric digit. Let's consider some examples:

"Universal Teacher Publications" Like "Univ*"
"Universal" Like "Univers??"
"ABC50" Like "ABC##"

All the above examples return the value 'True'.

"V" Like "[VBA]"

The above example shows a special kind of Like expression. If the character is like any character inside brackets, a 'True' is returned.

The Equality conditional operator would return false for these expressions because = does not recognize wildcard characters.

Always compare values whose data types are compatible. Don't try to compare a string and a number, because the results are usually wrong.